Phosphonoxycarboxamides

ABSTRACT

Novel phosphonoxycarboxamides of the formula: ##STR1## WHEREIN R 1  and R 2  are selected from the group consisting of aryl and alkyl having from 1-6 carbon atoms and may be the same or different; R 3  represents hydrogen or --CH 2  OH; R 4  represents hydrogen, --CH 3 , --CH 2  OH, or --C 2  H 4  OH, R 5  represents an alkyl group having from 1-5 carbon atoms; and n represents 1 or 2 are useful as flame retardant agents for textile materials.

TECHNICAL DISCLOSURE

This invention relates to new and useful phosphonoxycarboxamides andtheir method of preparation. More particularly, this invention relatesto new phosphonoxycarboxamide compounds which are useful as agents forimparting flame retardance to textile materials such as cotton fabric oryarn.

It has long been known that flame retardant properties may beincorporated into textile materials such as cotton fabric or yarn bytreatment with phosphorus-containing compounds. Such compounds areusually in the form of organophosphorus compounds which are relativelyharmless to the material being treated as well as resistant tolaundering.

More recently, it has been discovered that organic nitrogen is asynergist for phosphorus-induced flame retardance in cellulosic fabrics,and its presence in the flame-retardant compound permits a reduction inthe amount of flame retardant which is required to achieve an acceptabledegree of flame retardance. Exemplary of flame-retardant compounds whichcontain both nitrogen and phosphorus are those disclosed in U.S. Pat.Nos. 3,268,292; 3,374,292; 3,556,840; 3,634,422; 3,763,283; and3,835,204.

It is an object of this invention to provide a novel class ofphosphonoxycarboxamide compounds which are effective in imparting flameretardance to textile materials. It is another object of this inventionto provide novel compositions which may be used at relatively low add-onweights to impart flame retardance to textile compositions. It is afurther object of this invention to provide a novel process by whichflame retardancy may be imparted to textile materials.

In accordance with one aspect of this invention, there is provided acompound of the formula: ##STR2## WHEREIN R¹ and R² are selected fromthe group consisting of aryl and alkyl having from 1-6 carbon atoms andmay be the same or different; R³ represents hydrogen or --CH₂ OH; R⁴represents hydrogen, --CH₃, --CH₂ OH, or --C₂ H₄ OH, R⁵ represents analkyl group having from 1-5 carbon atoms, provided that only one of R³and R⁴ may be hydrogen; and n represents 1 or 2.

Within the broad class of compounds encompassed by this invention, aparticularly preferred subclass comprises those compounds wherein R¹represents an alkyl radical of from 1-4 carbon atoms; R² represents analkyl radical of from 1-2 carbon atoms; R³ represents hydrogen or --CH₂OH; R⁴ represents hydrogen, --CH₃, --CH₂ OH, or --CH₂ CH₂ OH, R⁵represents --CH₂ ; and n represents 1 or 2.

In accordance with another aspect of this invention, there is provided aflame-retardant composition comprising: (1) at least one compoundrepresented by the formula: ##STR3## wherein R¹ and R² are selected fromthe group consisting of aryl and alkyl having from 1-6 carbon atoms andmay be the same or different; R³ represents hydrogen or --CH₂ OH; R⁴represents hydrogen, --CH₃, --CH₂ OH, or --C₂ H₄ OH, R⁵ represents analkyl group having from 1-5 carbon atoms; and n represents 1 r 2; (2) anaminoplast; and (3) an acid catalyst. In preferred embodiments, theflame-retardant composition is an aqueous formulation wherein theaminoplast is present at a concentration ranging from about 10 to about600 percent by weight of the phosphonoxycarboxamide compound, the acidcatalyst is present at a concentration ranging from about 0.01 to about5 percent by weight of the phosphonoxycarboxamide, and the totalconcentration (i.e., the "solids" content) of thephosphonoxycarboxamide, aminoplast, and catalyst is adjusted to providea phosphorus uptake of 1 to 5% by weight on the fabric being treated.

In accordance with a further aspect of this invention, there is provideda process for imparting flame retardance to textile materials comprisingthe steps of impregnating the textile material with a flame-retardantcomposition comprising: (a) at least one compound represented by theformula: ##STR4## wherein R¹ and R² are selected from the groupconsisting of aryl and alkyl having from 1-6 carbon atoms and may be thesame or different; R³ represents hydrogen or --CH₂ OH; R⁴ representshydrogen, --CH₃, --CH₂ OH, or --C₂ H₄ OH; R⁵ represents an alkyl grouphaving from 1-5 carbon atoms; and n represents 1 or 2; (b) anaminoplast; and (c) an acid catalyst and heating the impregnated textilematerial to a temperature sufficient to cure the flame-retardantcomposition.

The phosphonoxycarboxamides of this invention may be prepared by avariety of techniques known in the art. For example, when n=1, they maybe prepared by reacting a carbalkoxy alkyl phosphonate such as acarbalkoxy methyl phosphonate, i.e., ##STR5## wherein R¹ and R² are asdefined hereinabove, and R⁶ represents an alkyl group having from 1 to 2carbon atoms; with ammonia, i.e., NH³ to form an N- unsubstitutedphosphonoxycarboxamide ##STR6## or with a primary amine such as, forexample, methyl amine, ethanolamine, or the like to form a partiallyN-substituted phosphonoxycarboxamide, e.g., ##STR7##

This reaction may be conducted in a solvent which is nonreactive towardseither the starting reagents or the resulting phosphonoxycarboxamide.Suitable solvents include, but are not limited to water, methanol,ethanol, ethylene glycol, diethyl ether, acetone, toluene, and the like,The reaction is conducted at a temperature ranging from about 0° C. toabout 40° C. and generally requires a reaction time ranging from about 2to 20 hours.

The phosphonoxy-bis-carboxamide compounds (i.e., Compound I wherein n=2)of this invention may be prepared using the same procedures as describedabove except that a bis-carbalkoxyalkyl phosphonate, i.e., ##STR8## isused as a starting material instead of a carbalkoxymethyl phosphonate(II).

The precursor phosphonates (Compounds II and IIA) used in preparing thenovel phosphonoxyacetamides of this invention may be prepared byreacting an alkyl, aryl, alkylaryl, or arylalkyl phosphonate with analkyl halo alkanoate at a temperature ranging from about 125° C. toabout 175° C. in the presence of an anionic catalyst such as sodiumcarbonate at a concentration ranging from about 0.2 percent to about 0.5percent by weight of total reaction mixture. This reaction is generallyconducted without a solvent and requires from about 8 to about 12 hoursat the stated temperature range. Typical alkyl phosphonates which may beused in preparing these precursor phosphonates include, but are notlimited to, dimethyl methylphosphonate, diethyl methyphosphonate,dimethyl ethylphosphonate, diethyl ethylphosphonate, dimethylbutylphosphonate, dipropyl butylphosphonate, dibutyl butylphosphonate,and the like.

Exemplary of the alkyl halo alkanoates which may be used to form theprecursor phosphonate compounds are methyl chloroacetate, ethylchloroacetate, ethylbromoacetate, and the like.

Thus, the formation of precursor phosphonates II and IIA may beillustrated schematically as follows. ##STR9##

The N- unsubstituted or partially substituted phosphonoxycarboxamideswhich are prepared by reacting the precursor phosphonates with eitherammonia or a primary amine may then be condensed with an aldehyde toform the alkyloamides. Aldehydes which may be used for this purposeinclude, but are not limited to, formaldehyde, acetaldehyde, andglyoxal. The alkylolamides may then be reacted with an aminoplast toform a water-insoluble resin. Aminoplasts which may be used for thispurpose include, but are not limited to, methylol- andmethoxymethylmelamines, methylolated ureas, and cyclic ureas such asdimethyloldihydroxyethyleneurea.

For example, Compound III may be methylolated by reaction withformaldehyde, which can be in gaseous, liquid solution, or solid form,over a period of from about 0.5 to about 2 hours at a temperatureranging from about 55° to about 85° C. while maintaining the system atan alkaline pH, preferably in the range of about 7.5 to about 8.5. Theproduct of this reaction using Compound III will be a mixture of themonomethylol substituted derivative (V) and the dimethylol derivative(VI): ##STR10## wherein the specific proportions of the mono- anddimenthylol derivatives within the mixture depends, in part, upon themolar ratio of the formaldehyde relative to the unsubstitutedphosphonoxycarboxamide present in the initial reaction mixture. Althoughcompletely satisfactory in this form for most applications, it isunderstood that, if desired, the reaction product may be further refinedby techniques well-known in the art to obtain the desired compound in amore pure form such as, for example, by crystallization.

The partially substituted phosphonoxycarboxamides (i.e., Compounds IVA,IVB) may also be reacted with formaldehyde to form N-methylolsubstituted derivatives, i.e., ##STR11## Exemplaryphosphonoxycarboxamides of this invention are: O-methylmethylphosphonoxyacetamide: ##STR12## N-methylol, O-methylmethylphosphonoxyacetamide: ##STR13## N-methyl-N-methylol. O-methylmethylphosphonoxyacetamide: ##STR14## N,N-dimethylol, O-methylmethylphosphonoxyacetamide: ##STR15## O-methylethylphosphonoxyacetamide: ##STR16## O-ethyl ethylphosphonoxyacetamide:##STR17## N-methylol, O-ethyl ethylphosphonoxyacetamide: ##STR18##N-methyl, N-hydroxyethyl, O-ethyl ethylphosphonoxyacetamide: ##STR19##Bis (carbamidomethyl) methylphosphonate: ##STR20## Bis (carbamidomethyl)ethyl phosphonate: ##STR21## Bis (dimethylol carbamidomethyl) ethylphosphonate: ##STR22## Bis (N-methyl-N-methylol carbamidomethyl)methylphosphonate: ##STR23##

The unsubstituted phosphonoxycarboxamides of structure (III) and thepartially substituted phosphonoxycarboxamides of structure (IV) areuseful in their own right since they can be bonded to a textile by meansof a reaction with an aminoplast. Thus, for example, a compound ofstructure (III) such as is illustrated by O-methylmethylphosphonoxyacetamide can be admixed with about 0.2 to 5 parts byweight of tri-, tetra-, or pentamethylolated melamine, or a partiallyetherified derivative thereof, and cured in the presence of an acidcatalyst such as those hereinabove described so as to yield durableflame retardant finishes on cellulosic, cellulosepolyester, or othertextiles. Methylolation of the phosphonoxycarboxamide does, however,offer the advantage of making it reactive with cellulose as well as withthe aminoplast and thus generally minimizes the amount of aminoplastwhich is required.

The phosphonoxycarboxamides of this invention may be applied to normallyflammable substrates in the form of an aqueous flame retardantformulation or as a liquid formulation in any of the organic solventscommonly used in the solvent finishing of textiles including, forexample, ethanol, methanol, chloroform, water and mixtures thereof.Preferably, these formulations also include an aminoplast and an acidcatalyst.

The term "aminoplast" is here meant to denote a nitrogen-containingresin which is capable of reacting with itself, with thephosphonoxycarboxamide, and/or with the textile or other substrate, andwhich is prepared by the polycondensation of formaldehyde with acompound having at least two reactive amino or amido hydrogen atoms.Exemplary of the aminoplasts which may be used are methylolureas whichmay be either straight chained or cyclic, methylolmelamines,methylolcarbamates, methylolurons, methylolamides, the methyl ethers ofthe above listed methylol compounds, methylolated acid amides, ureaglyoxal condensation products, urea-glyoxalformaldehyde condensationproducts, N-methylolated or N,N-dimenthylolated O-alkyl, O-alkoxy, orO-hydroxyalkyl carbamates. Preferred aminoplasts includetris(methoxymethyl) melamine as sold by the American Cyanamid Companyunder the trademark "AEROTEX M-3"; partially methylated melamine as soldby the American Cyanamid Company under the trademark "AEROTEX 23SPECIAL"; demethylolethylene urea; dimethylol dihydroxyethylene urea,dimethylol methyl carbamate, dimethylol hydroxyethyl/hydroxypropylcarbamate, and dimethoxymethyl uron. For most purposes, the use of oneor more of the above-described aminoplasts at a concentration rangingfrom 10 to 600 percent and preferably from about 25 to 300 percent byweight of the phosphonoxyacetamide will be satisfactory.

Suitable acidic catalysts for use in the flame-retardant compositions ofthis invention include mineral acids such as phosphoric acid; organicacids such as oxalic, citric, succinic, maleic, glycolic, chloroacetic,and toluenesulfonic acids; alkyl acid phosphates, and the like. Alsoincluded are the salts of strong acids with relatively weak bases suchas, for example, zinc nitrate, zinc chloride, magnesium chloride,ammonium chloride, ammonium phosphates, and amine hydrochlorides. Sometypical amine hydrochlorides include 2-amino-2-methylpropanolhydrochloride sold under the tradename "Catalyst AC" by the MonosantoCompany, and the alkanolamine hydrochloride sold as "Catalyst XRF" bythe Millmaster Onyx Corporation. The use of one or more of thesecatalysts in a concentration of from about 0.01 to 5 percent based onthe weight of the phosphonoxyacetamide will be suitable for mostpurposes.

The concentration (i.e., the "solids" content) of thephosphonoxycarboxamide/aminoplast/catalyst composition used may vary inaccordance with several factors such as the nature of the substrate orfabric to which it is being applied, the amount ofphosphonoxycarboxamide resin desired in or on the final product, and thelike. It is generally desirable, however, to achieve a phosphorousuptake on the textile or other substrate ranging from about 1 to about 5percent by weight of the dry untreated fabric or substrate. Thus, theconcentration of the flame-retardant composition will be adjusted to asolids level which will produce the desired amount of phosphorous uptakewith the anticipated amount of wet-pickup. The ranges given, of course,are merely illustrative and may be varied in accordance with theparticular needs of the user.

The flame-retardant composition containing the phosphonoxycarboxamide,aminoplast, and catalyst may be applied to textiles or other substratesby the use of any of those techniques known in the art for this purposesuch as dipping, spraying, painting, padding, etc. A preferred methodfor applying the composition to a fabric is that known as "padding"wherein the fabric is passed or "padded" through the composition whilethe latter is being held in a tank or other suitable container. For mostapplications, it is desirable to maintain the pH of the padding bath inthe range of from about 4.5 to about 5.5.

The thus applied flame-retardant composition may then be dried andcured. Drying may be accomplished by various techniques includingheating at a temperature ranging from room temperature up to about 120°C. or higher. It is, of course, entirely possible to eliminate drying asa separate step and accomplish the drying as a part of the curing step.Curing may be accomplished by heating at a temperature ranging fromabout 130° C. to about 180° C. with temperatures in the range of fromabout 150° to 160° C. being preferred. Curing time may vary from about 1minute to about 20 minutes depending on the nature of the substratebeing treated. The effect of the curing operation is to cause thealkylolated phosphonoxycarboxamide and aminoplast to react with thecellulose or with each other so as to form a crosslinked, insolublefinish in and/or on the individual fibers comprising the textile orother flammable structure.

As used herein, the term "flame retardant" is intended to refer to thatparticular property of a material which provides it with a degree ofresistance to ignition and burning. Thus, a fire or flame retardanttextile, paper, or other solid substrate is one which has a low level offlammability and flame spread. This property may be convenientlyevaluated by means of any of the standard flame retardancy tests suchas, for example, the vertical char length tests described in the federalFlammability Standard of July 27, 1971 (35 Federal Register 146).

As used herein, the term "textile" or "textiles" is meant to encompasswoven or knitted fabrics as well as nonwoven fabrics which consist ofcontinuous or discontinuous fibers bonded so as to form a fabric bymechanical entanglement, thermal interfiber bonding, or by use ofadhesive or bonding substances. Such non-woven fabrics may contain acertain percentage, up to 100 percent, of wood pulp as well asconventional textile fibers in which case part of the bonding process isachieved by means of hydrogen bonding between the cellulosic pulpfibers. In non-woven fabrics, the compounds of this invention can servenot only as flame retardant finishes but can also contribute to theinterfiber bonding mechanism by serving as all or part of the adhesiveor bonding resin component. This dual role can also be played by thephosphonoxycarboxamides of this invention in fabric laminates where theycan at the same time serve as the interlaminar bonding agent and as theflame retardant. In both of these systems, i.e., non-woven fabrics andlaminated fabrics, the compounds of this invention can also be blendedwith the usual bonding agents such as, for example, acrylic enulsionpolymers, vinyl acetate homo- and copolymer emulsions, styrenebutadienerubber emulsions, urethane resin emulsions, polyvinyl chlorideemulsions, vinyl chloride-alkyl acrylate copolymer emulsions,polyacrylates modified by vinyl carboxylic acid comonomers, and thelike.

The preparation and use of the novel phosphonoxycarboxamide compounds ofthis invention is further illustrated by the following nonlimitingexamples, all parts and percentages given being by weight unlessotherwise stated.

EXAMPLE 1

This example illustrates the preparation of O-methylO-carbomethoxymethyl methylphosphonate to be used as a precursor inpreparing the phosphonoxycarboxamides of this invention.

1118 grams (9 moles) of dimethyl methylphosphonate was mixed with 653.5grams (6 moles) methyl chloroacetate and 4.0 grams sodium carbonate(catalyst) in a flask equipped with a stirrer, an overhead condenser,and a condensate trap. The reaction mixture was heated over severalhours to a temperature of 128° C. during which period some methylchloride was collected in the condensate trap. The reaction mixture wasbrought to a temperature of 130°-131° C. and held there for severalhours during which time 239 grams of methyl chloride was collected inthe distillate trap. Increasing the temperature to 138° C. for one hourproduced an additional 28 grams of methyl chloride.

The reaction product was then stripped in a 1-foot vigreux column toremove excess dimethyl methylphosphonate. A first distillate fraction,weighing 509.5 grams, was taken off at a column pressure of 24 mm. Hg.abs., a base temperature of up to 119° C., and an overhead vaportemperature of up to 87° C.; and a second distillate fraction, weighing150 grams, was taken off at a column pressure of 0.1 mm. Hg. abs., abase temperature up to 100° C., and an overhead vapor temperature up to40° C. The total amount of distillate collected, 659.5 grams, exceededthe theoretical amount by 123.5 grams. This excess was attributed tounsubstituted dimethyl methylphosphate remaining in the reaction mixturedue to the disubstitution of a corresponding amount of the desiredproduct by an extra mole of methyl chloroacetate.

The crude reaction product remaining after distillation had an acidityto bromothymol blue equivalent to 0.18 milliequivalents acid per gram.

EXAMPLE 2

This example illustrates the preparation of the N-unsubstitutedphosphonoxycarboxamides of this invention from the O-methylO-carbomethoxymethyl methylphosphonate prepared in Example 1.

Fifty grams of anhydrous ammonia was dissolved in 700 ml. of methanol toprepare a 4.43 normal solution. 125 ml. of this solution was slowlyadded to the O-methyl carbomethoxymethyl methylphosphonate prepared inExample 1 at a temperature of 10°-15° C. This reaction mixture was thenallowed to stand overnight at room temperature.

The next day, an additional 545 ml. of the 4.43 normal ammonia solutionwas added to the reaction mixture at reduced temperature followed by 220ml. of a similarly prepared 9.3 molar ammonia solution. Following thisaddition, a 1.0 ml. sample of the reaction product was found to have0.21 meq. ammonia (to bromothymol blue). The reaction mixture was heatedto 46° C. for two hours after which it was found to contain 0.18 meq.ammonia/ml. and 0.4 meq. R N⁺ H₃ /ml. The reaction product was thenstripped of methanol to a final weight of 781 grams.

275 ml. of tetrahydrofuran and a few seed crystals were added to 760grams of the stripped product. The resulting precipitate was filteredout and washed three times with butanol to yield 375 grams ofcrystalline product having a melting point of 40°-48° C. This productwas recrystallized in 200 grams of ethanol and then washed withmethyl-ethyl ketone to yield 210.5 grams of a crystalline product havinga melting point of 50°-55° C. Infrared analysis of this productindicated that C═O and P═O were present in a 1:1 ratio.

EXAMPLE 3

This example illustrates the N- substitution of thephosphonoxycarboxamide prepared in Example 2.

200 grams of the phosphonoxycarboxamide prepared in Example 2 and 42grams of paraformaldehyde (95 percent formaldehyde) were heated to 80°C. and stirred for one hour. All of the paraformaldehyde dissolved,indicating that reaction had taken place.

EXAMPLE 4

This example illustrates the preparation of a bis carbalkoxymethylphosphonate precursor used in preparing the bis(carbamidomethyl)phosphonates of this invention.

167.5 grams of dimethyl methyl phosphonate was heated to 125° C. in aflask equipped with a stirrer, an overhead condenser, and a condensatetrap. 0.5 gram of tetraethylammonium chloride was stirred in, and then457 grams of ethyl bromoacetate was added over a period of about 21/2hours. As the ethyl bromoacetate was being added, the reactiontemperature increased to a maximum of 170° C., and methyl bromide vaporswere condensed in the overhead condenser and collected in the condensatetrap. Upon completion of the addition of the ethyl bromoacetate to theflask, the reaction mixture was allowed to cool to room temperature. Atthis time, the condensate trap was found to contain 217.3 grams ofmethyl bromide. The flask contents were then reheated to a temperatureranging from about 162° C. to about 165° C. for about 11/2 hours duringwhich time an additional 14 grams of methyl bromide was collected in thecondensate trap. Upon cooling, the flask was found to contain 394 gramsof product in the form of a yellow fluid. This compares to a calculated(theoretical) yield of 368 grams.

EXAMPLE 5

This example illustrates the preparation of bis(carbamidomethyl)methylphosphonate from the bis (carbalkoxymethyl) methylphosphonateprecursor prepared in Example 4.

Forty-seven grams of anhydrous ammonia was dissolved in ethanol toprepare 660 ml. of a 4.15 molar solution. This solution was then addedat room temperature to the product of Example 4, with no observableexotherm resulting. The reaction mixture was allowed to stand in an icebath for three days. When subsequently heated to 65° C. under a dry-icedephlegmator, no ammonia condensed out; this was taken as an indicationthat the reaction had been completed. The reaction mixture was thenstripped of ethanol under vacuum to a weight of 394 grams and then Hivacstripped to a final weight of 366 grams (compared to a theoreticalweight of 290 grams). Infrared analysis indicated the presence of someremaining ester functionality. A sample of the reaction mixture wastitrated to the thymolphthalein end point which indicated the presenceof about 0.4 mole of NH₄ ⁺. Seven grams of ammonia in 35 ml. of methanolwas then added and the reaction mixture allowed to stand overnight at43° C. Titration of a sample of the reaction mixture with acid indicatedthat the entire reaction mixture contained about 70 meq. NH₃. Thereaction mixture was then heated for 29 hours at a temperature rangingfrom 40°-45° C. Subsequent analysis indicated the presence of 25 meq. ofammonia.

The reaction mixture was then stripped of methanol at a temperature of62° C. and a pressure of 0.1 mm. abs. to a final product weight of 345grams.

EXAMPLE 6

This example illustrates the preparation of a flame retardant textilefinish with the phosphonoxycarboxamides of this invention.

An aqueous padding bath was prepared containing 54.9 percent by weightof water, 0.1 percent by weight of "TRITON X-100", an ethoxylatedtertiary-octylphenol condensate wetting agent sold by the Rohm and HaasCompany, 30 percent by weight of N-methylol, O-methylmethylphosphonoxyacetamide (i.e.., Compound (2), 10 percent by weight oftris (methoxymethyl) melamine, an aminoplast obtained from the AmericanCyanamid Company under the tradename "AEROTEX 23 SPECIAL", and 5 percentby weight of ammonium chloride (as catalyst). A sample of cotton flannelcloth having a weight of 3.8 oz./sq. yard was padded through the aqueouspadding bath and then dried at 250° F. (121.1° C.) for 11/2 hours andcured at 350° F. (176.7° C.) for two hours. Dry add-on weight was foundto be 24.2 percent by weight of untreated cloth.

The treated flannel cloth was then subjected to a series of ten hotwater, i.e., 60° C., detergent washes in a home washing machinecontaining 50 grams of "Tide XK", a strong laundry detergent sold by theProctor and Gamble Company, and 200 parts per million of water hardness(calculated as CaCO₃ using Mg. (NO₃)₂.6H₂ O and Ca(NO₃)₂.4H₂ O) andeight bath towels as ballast.

The flammability of the cloth was evaluated before and after washing bymeans of a modified vertical char length test. In the vertical charlength test, the complete details of which are described in the FederalFlammability Standard of July 27, 1971, (35 Federal Register 146), a10-inch strip of the finished cloth is suspended vertically so that itslower edge is maintained 3/4 inch (1.9CH) above the top of a Bunsenburner having a 1.5-inch (3.81 cm) high flame for a period of threeseconds. The length of the resulting char, in inches, is then measuredupward from the base of the strip. Thus, a shorter char length of about3 to 5 (7.6 to 12.7 cm) is indicative of a greater degree of fireretardancy while a char length of about 10 inches (25.4 cm) (burned itsentire length) is unacceptable for most applications. The hand and colorof the cloth samples were also evaluated before and after washing. Forthis experiment, the drying conditions were modified to those givenabove, and an 8-inch strip of cloth was used instead of a 10-inch strip.The results of these evaluations were as follows:

    ______________________________________                                                  Vertical                                                                      Char (inches)                                                                          Hand      Color                                            ______________________________________                                        Before Washing                                                                            4.25"(10.8cm)                                                                            2.0       Light Yellow                                 After Washing                                                                             6.5" (16.5cm)                                                                            1.5       White                                        ______________________________________                                    

EXAMPLE 7

This example illustrates the preparation of a flame retardant finishwith a bis-phosphonoxycarboxamide of this invention.

An aqueous padding bath was prepared as in Example 6 except that theO-methyl methylphosphonoxyacetamide of Example 7 was replaced by amethylolated bis(carbamidomethyl) methylphosphonate, i.e., Compound(11). A sample of the same cotton flannel cloth as was used in Example 6was padded through the aqueous padding bath, dried, and cured as inExample 6. Dry add-on weight was found to be 21.8 percent by weight ofuntreated cloth.

The treated cloth was washed and evaluated for flammability, hand, andcolor as in Example 6 with the following results:

    ______________________________________                                                  Vertical                                                                      Char (inches)                                                                          Hand        Color                                          ______________________________________                                        Before Washing                                                                            4.5"(11.4 cm)                                                                            2.0         Brown                                      After Washing                                                                             *B.E.L.    1           Tan                                        ______________________________________                                         *Burned entire length.                                                   

It was found that the flame retardancy "before washing" produced by thebis (carbamidomethyl) methyl phosphonate was roughly equivalent to thatof the monocarbamidomethyl methyl phosphonate of Example 6. The flameretardancy after washing 10 times was judged to be unacceptable. thus,either compound may be used to achieve effective flame retardancy inapplications which are not subject to laundering; but for thoseapplications subject to laundering, the mono-carbamidomethylmethyl-phosphonate should be used.

It may thus be seen that the novel phosphonoxycarboxamide compounds ofthis invention are effective in imparting flame retardance to textilematerials. The novel flame-retardant compositions of this inventionimpart flame retardance to textile materials at reasonable add-onweights, thereby making them highly desirable for use in textiles fromwhich light weight articles of clothing are to be manufactured. Thetextiles to be made flame retardant may be effectively and convenientlytreated to impart flame retardance to them by the process of thisinvention. The objects set forth above, among those made apparent fromthe preceding description, are therefore effectively attained.

Since certain changes may be made in the above compounds, compositions,and process without departing from the scope of this invention, it isintended that all matter contained in the above description shall beinterpreted as illustrative and not in a limiting sense.

What is claimed is:
 1. A compound of the formula ##STR24## wherein R¹and R² are selected from the group consisting of aryl and alkyl havingfrom 1-6 carbon atoms and may be the same or different; R³ representshydrogen or --CH₂ OH; R⁴ represents hydrogen, --CH₃, --CH₂ OH, or --C₂H₄ OH, R⁵ represents --CH₂ --, and n represents 1 or
 2. 2. A compound inaccordance with claim 1 wherein R¹ represents an alkyl radical of from1-4 carbon atoms, R² represents an alkyl radical of from 1-2 carbonatoms.
 3. A compound in accordance with claim 1 wherein n is
 1. 4. Acompound in accordance with claim 3 wherein R¹ is methyl, R² is methyl,at least one of R³ and R⁴ is methylol, and R⁵ is methyl.
 5. A compoundin accordance with claim 1 wherein n is
 2. 6. A compound in accordancewith claim 5 wherein R¹ is methyl, R² is methyl, and at least one of R³and R⁴ is methylol.